Beijing receives water from south, but doubts remain(2)

He also said river sand will eventually destroy the middle route of the water project. Water from Danjiangkou Reservoir contains large amounts of sand, but the designers insisted on discharging it directly into the main canal.

The main canal of the middle route is 1,432 km in length, featuring a 1,196.36-km-long open channel. Ma Ke'an said the water may freeze en route and fail to arrive in Beijing.

In response to these doubts, Xinhua interviewed Wang Hao, an academician with the Chinese Academy of Engineering and a famous water expert.

Ma's calculation is based on the motion trail of rubber duck with GPS and camera, which was put into the water in central China's Henan Province by an engineer.

The method was "unreliable" with an "unscientific conclusion", Wang told Xinhua. "Based on official calculations, the normal water flow rate should be one to 1.5 meters per second."

In addition, 9.5 billion cubic meters of water is an average figure. During years with heavy rain, the middle route can supply more than 12 billion cubic meters of water, while in dry years it will provide less.

Moreover, Wang said the Yangtze River has a low sediment load with only one kilograms per cubic meter. Since 2006, China has invested more than 10 billion yuan to prevent and treat water pollution and conserve soil in Danjiangkou Reservoir and its upper reaches.

"So it is ridiculous to say water from the south will have much more sediment," he said.

Wang Hao admitted transporting water in winter is one of the important problems the project has been facing. But plans are in place to prevent freezing.

One plan is to increase the water capacity during the frozen period to ensure water can flow under the icy surface. Other plans include de-icing facilities used along the route.

According to the Beijing office of the South-to-North Water Diversion Project, the project will operate in winter despite freezing rivers in certain sections north of Anyang City in Henan.

The huge project has been widely hailed as an example that the Chinese people are capable to bettering their lives through hard efforts. But since the project was conceived, debate has not ceased.

Just like people worrying about the water quality, they also express concerns about pollution. Some say the scheme's success may damage the water cycle balance and have an adverse impact on local ecology.

Critics even say it will only temporarily quench the thirst in the north.

"Despite those doubts and criticism, time will tell the truth," Mao Wei said.